Ultra Wideband (UWB), an impulse carrier waveform, was applied at HF-VHF frequencies to utilize surface wave propagation. Due to the low duty cycle of the pulse, the energy requirements are significantly reduced. UWB involves the propagation of transient pulses rather than continuous waves which makes the system easier to implement, inexpensive and small. The use of surface wave propagation (in...

This paper presents a new laser lock-in thermography (LLT) technique for nondestructive evaluation. LLT utilizes a modulated continuous wave laser beam as a heat source to obtain high fidelity thermal wave images even at the presence of background heat disturbances. The thermal waves propagating along the surface and through-the-thickness directions of a structure are visualized using newly dev...

Surface modes in nanostructured metallic metamaterial films are reported showing larger confinement than plasmons in metallic waveguides of similar dimensions, but in contrast to plasmons, the new modes have TE polarization. The metamaterial, formed by planar arrays of nearly-touching metallic nanoparticles, behaves as a high-index dielectric for the noted polarization, thus yielding well confi...

It has been demonstrated in the rodent hippocampus that rhythmic slow activity (theta) predominantly occurs during rapid eye movement (REM) sleep, while sharp waves and associated ripples occur mainly during non-REM sleep. However, evidence is lacking for correlates of sleep stages with electroencephalogram (EEG) in the hippocampus of monkeys. In the present study, we recorded hippocampal EEG f...